unable to boot after install of some kexts
 

can some help me i installed some kexts now i cant boot when i boot with -v i get to errors in yellow that say unable to find drivers com.apple.driver.appleacpiplatform and com,psystar.driver.openhaltrestart.

Try -v -x -F. If this lets you in, restore the ACPI driver as my guess is that's where your trouble lies.

It is also a good idea to backup both your Extensions folder and your kernel once you get a working system. You could then boot into Single User Mode (-s) and manually replace those kexts.

To backup your Extensions folder:
1. First we will make a directory called "backup" in our root directory to store them. Open Terminal and type:
2. Copy your kexts to the new "backup" folder.
To backup your kernel:
1. Open Terminal and type the following:
Now if your kernel gets replaced you can boot using the boot-option mach_kernel.backup and it will load your backup kernel.

i tryed -v-x-F still nothing just asks me to reboot do i have to re-install it?

try "-s" and try to restore your old kexts

Do you remember the exact kexts which you installed? We may be able to help you avoid a complete reinstall but will need to know a bit more.